Fusible link

ABSTRACT

A fusible link is provided suitable for use for controlling a weight release, for a door closer or for a sprinkler, which can be used in tension or compression, and which includes two link elements one interengaged with the other and held against movement by a transverse fusible temperature responsive retainer.

D United States Patent [111 3,779,004

Gloeckler Dec. 18, 1973 1 FUSIBLE LINK 2,904,866 9/1959 Carter 24 201 1) 3,089.568 4 .5 [75] Inventor: Fred A. Gloeckler, Huntington 3597309 f 2 Valley, 3.725.972 4/1973 McCabe 16/485 [73] Assignee: Star Sprinkler Corporation of Flonda Phlladelphla Primary EraminerCharles W. Lanham [22] Filed: Sept. 12, 1972 Assistant Examiner-Gene P. Crosby 1 pp No: 288,280 Atl0rne v-Zachary T. Wobensmtth, ll

[52] US. Cl 59/93, 16/485, 24/201 LP, [57] ABSTRACT 49/8 [51 Il'lt. Cl. F16g 15/00 A f i i provided Suitable for use for control [58] Field Of Search 59/93, 86, 85, 78; ling a weight release, for a door closer or for a Sprin 24/201 201 116 H5 31 L; 49/8 kler, which can be used in tension or compression,

1; 16/485 and which includes two link elements one interengaged with the other and held against movement by a [56] References C'ted transverse fusible temperature responsive retainer.

UNITED STATES PATENTS 1,826,553 10/1931 Lasier 16/485 7 Claims, 5 Drawing Figures FUSIBLE' LINK Withrthepassage of time and-without beingsubjected to the elevatedtemperatureat which. release is to occur, thoseslinks fail: by. reasonofa creep action which is a characteristic otfitheeutectic alloy.

In other fusible. links, because of their construction,

ratingwas limited to 360 F. for a loadinginthe' range from. 3 to.40 pounds.

The: link of the present invention. is suit'able: for" a. higher range of temperature to include500 F. and a wider load range offthe ordersof l to50 pounds.

SUMMARY OF THE INVENTION In accordance with the invention, a fusible link is provided comprising interengaging link portions, one of the link portionshaving an aperture through which an integral loop orstaple of theother link. portionextends, a: transversely disposedtemperature responsive strut member with a. fusible insert beingpositionedim and engaging: the loop or staple and opposite margins of the apertureand disengageduponbeing subjected to a predetermined: temperature.

It isthe principalobject of theinvention to provide a fusible link. which is simplein construction, reliable inoperation, free from operatingdifficulties and'likelihood:ofi failureprior: to release by exposure to a predetermined temperaturei It is a further object of the invention to provide a fusible link which-has a wider available operating range than fusible links heretofore available.

ltis afurther object of the invention to provide a fus ible link of the character aforesaid which willbe relatively inexpensiveto manufacture.

Other objects and advantageousfeatures of the invention will: be apparent from the description: and claims.

BRIEF DESCRIPTION OF THE DRAWINGS Thenature and characteristic features of the invention willbe more readily understoodfromthe following descriptiontakeninconnection with the accompanying drawings forming part'thereof, inwhich:

FIG. .L-is aperspective'view ofthe link andunder tenston;

FIG. 2 is a longitudinalsectionall view on the line FIG. 3*is a transverse'sectional view on the line 3-3 of' FIG. 1

FIG. 4-is an explodedperspective view; and

FIG; 5 is a view similar to FIG. I withthe link under compression.

Itshould, of course, be understoodthatthe description and drawings herein are' illustrative merely and thatvarious modifications and changes can be made in the structure disclosed without departing from the spirit of the invention.

Like numerals refer to like parts throughout the several views.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referringnow more-particularly to thedrawings, the

rectangular body 12 and an end l3 with an opening I for attachment at the place of use.

The body l2has a central opening 15 of generally rectangular shape withopposite parallel side margins 17 and 18*andopposite parallel end margins l9 and "20.

A second link portion25 is provided, preferably also made as-a sheet metal stamping, witha generally rectangular body 26 and amend 27 with anopening 28 for attachment at the place of use.

The body 26 has an integral loop or staple 29 of rounded V-shaped extending out of the mainplane of body 26, whichis narrower than the distance between the sidemargins l7and 18an d is disposed through the central opening 15 of the first link portion 1 1, between the side margins 17 and 18 and ine'ngagement with the end margins Hand 20'. The outerface 30 has a camming action with one of the margins 19 or 20 as herein after pointed out.

The second link portion 25, with the loop or staple 29 through the opening 15 has the contiguous portion of its body 26 in flat or face'to face relation to the body 12 of the first loop portion.

The loop or staple 29*hasapair of integral spaced fingers 31 in the same plane as the body 26 which extend through the opening 15 past'the endmargin l9and in contact with the same face of the body 12 with which the body 26 is in flat engagement.

A temperature responsive strut35 is providedto hold the link portions 11 and 20 in assembled'relation for use.

The strut 35has a strut body 36 with a rounded end 37 and a hollow interior or cavity 38. Withinthe cavity 38 a pellet 39 of eutectic fusible alloy of wellknown type is provided and which may have melting temperatures of 212, 286, 360, 400, or 500 ,F or other melting temperature as desired.

Adisc 40 retains the pellet 39in cavity 38 anddistributes the load from a ball 4l which bears against the disc 40;

The ball 41 is seated in a recess 42in the body along the margin 18. Theend 37 is seated in a recess43 along the margin 17.

The mode of operation will now 'be pointedout.

With thefusible link 10 in assembled conditionthe link 10 can be employed for various purposes, intension or compression as required, including the control Whenthe temperature in the vicinity of the link 10- is reachedwhichis the melting'temperature of the pellet 39, the pellet 39 melts so that the ball 41 which is no longer held by the pellet 39 and disc 40, moves in-' wardly within the cavity 38. The pressure applied by the relatively snugfit of the strut 3Swithin the staple 29 and the engagement of the ball 41 and rounded end 37 in the recesses 42 and 43 aids in the longitudinal collapse of the strut 35.

The force applied on the link portions 11 and 25 is effective for separating the link portions 11 and 25 since they are no longer retained by the strut 35.

If the link portions 11 and 25 are in tension the outer face 30 of the staple 29 has a camming action against the end margin 20 to aid in the shortening of link and separation of the link portions 11 and 25.

If the link portions 11 and 25 are in compression the outer face of the staple 29 has a camming action against the end margin 19 to aid in the shortening of the link 10 and separation of link portions 11 and 25.

I claim:

1. A fusible link comprising a first link portion having an opening therethrough,

a second link portion having an integral staple extending therethrough, and

a transverse strut disposed within said staple and in engagement therewith and with said first link portion,

said transverse strut having therein a portion of eutectic alloy with a predetermined melting temperature normally holding said strut in place but being collapsible upon melting of said eutectic alloy.

2. A fusible link as defined in claim 1 in which said first link portion has a flat body in which said opening is located,

said second link portion has a flat body from which said staple extends.

3. A fusible link as defined in claim 2 in which said body of said second link portion is disposed in face to face relation to the body'of said first link portion on one side face thereof.

4. A fusible link as defined in claim 3 in which said staple has an extension in engagement with said side face of said first link portion.

5. A fusible link as defined in claim 1 in which said strut has ends in engagement withvsaid first link portion at opposite sides of said opening.

6. A fusible link as definedin claim 1 in which said opening has end margins, and

said staple has an outer face portion for camming engagement with one of said end margins upon release of said strut by melting of said eutectic alloy.

7. A fusible link as defined in claim 1 inwhich said staple is of lesser width than said opening, and

said strut is of greater width than said opening and is normally engaged with said first link portion at the side margins of said opening. 

1. A fusible link comprising a first link portion having an opening therethrough, a second link portion having an integral staple extending therethrough, and a transverse strut diSposed within said staple and in engagement therewith and with said first link portion, said transverse strut having therein a portion of eutectic alloy with a predetermined melting temperature normally holding said strut in place but being collapsible upon melting of said eutectic alloy.
 2. A fusible link as defined in claim 1 in which said first link portion has a flat body in which said opening is located, said second link portion has a flat body from which said staple extends.
 3. A fusible link as defined in claim 2 in which said body of said second link portion is disposed in face to face relation to the body of said first link portion on one side face thereof.
 4. A fusible link as defined in claim 3 in which said staple has an extension in engagement with said side face of said first link portion.
 5. A fusible link as defined in claim 1 in which said strut has ends in engagement with said first link portion at opposite sides of said opening.
 6. A fusible link as defined in claim 1 in which said opening has end margins, and said staple has an outer face portion for camming engagement with one of said end margins upon release of said strut by melting of said eutectic alloy.
 7. A fusible link as defined in claim 1 in which said staple is of lesser width than said opening, and said strut is of greater width than said opening and is normally engaged with said first link portion at the side margins of said opening. 